fix: ensure connection encodes utf8 correctly

[GordonSmith]

Checklist:

• The commit message is properly formatted and free of typos.
  • The commit message title makes sense in a changelog, by itself.
  • The commit message includes a "fixes" reference if appropriate.
  • The commit is signed.
• The change has been fully tested:
  • I have viewed all related gallery items
  • I have viewed all related dermatology items
• There are no similar instances of the same problem that should be addressed
  • I have addressed them here
  • I have raised new issues to address them separately

Testing:

[Copilot]

Pull request overview

This PR replaces the btoa polyfill with a custom utf8ToBase64 utility function to properly handle UTF-8 encoding in authentication headers. The original btoa implementation in Node.js incorrectly encoded multi-byte UTF-8 characters, which could cause authentication failures when usernames or passwords contain non-ASCII characters.

Key Changes:

• Created a new utf8ToBase64 utility function with proper UTF-8 encoding support for both Node.js and browser environments
• Replaced btoa usage in the authentication header generation with the new utility
• Removed the problematic btoa polyfill from Node.js initialization code

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
packages/util/src/utf8ToBase64.ts	New utility function that properly encodes UTF-8 strings to Base64, with fallbacks for different environments
packages/util/tests/utf8ToBase64.spec.ts	Browser-compatible tests for ASCII and nullish value handling
packages/util/tests/utf8ToBase64.node.spec.ts	Node.js-specific tests for multi-byte character encoding and fallback behavior
packages/util/src/index.ts	Exports the new utf8ToBase64 function
packages/comms/src/connection.ts	Updated to import and use utf8ToBase64 instead of btoa for authentication header
packages/comms/src/index.node.ts	Removed the problematic btoa polyfill and moved Buffer import
packages/comms/src/index.common.ts	Minor whitespace cleanup
packages/comms/index.html	Added console logging for debugging workunit operations
packages/comms/.vscode/launch.json	Updated local development server port

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

You can also share your feedback on Copilot code review for a chance to win a $100 gift card. Take the survey.

[jeclrsg]

@GordonSmith looked good to me, just a couple of nitpicks